code: def test_popmon_module(test_module):
      datastore = {"x": np.arange(10)}
      datastore = test_module.transform(datastore)
  
      assert (
          "x" in datastore
      )  # check if key 'x' is still in the datastore
      np.testing.assert_almost_equal(
          np.mean(datastore["scaled_x"]), 2.0, decimal=5
      )
      np.testing.assert_almost_equal(
          np.std(datastore["scaled_x"]), 0.3, decimal=5
      )
  
file_path: popmon/tests/popmon/base/test_module.py
imports: import numpy
  import pytest
  from popmon.base import Module
label_desc: Use image node_id 2 for calling a global function with example usage: test_popmon_module(test_module) without return types